Vilter VSM 71-701, Operation And Service Manual

Page: 91 / 244

91
Service
5.00 LIQUID INJECTION PLUG
REPLACMENT
A) Electrically lock out and tag out the screw
compressor package.
B) Isolate the screw compressor package
from the package.
C) Remove the refrigerant from the screw
compressor package in an approved man-
ner.
5.01 REMOVAL OF PLUG
A) Remove the socket head pipe plug, from
the top of VSS compressors or the bot-
tom of VSR compressors. Some of the
pipe plugs were sealed with red refriger-
ant grade thread sealing compound. This
may require a moderate amount of heat
to be applied to the plug, not to exceed
300°F.
B) Two types of inner plugs are used.
1) The first style of plug assemblies
consists of a steel plug with a
crushed Teflon
®
pellet on top of the
steel plug, which holds the steel
plug in position. To remove the
steel plug, the crushed Teflon pel-
let must be dug out from the top of
the steel plug. Care must be taken
that all of the Teflon is removed
from the threads.
2) After the threads are clean, the steel
plug can be removed with a ¼” x
20 threaded rod or bolt. After the
plug is removed, clean and inspect
the port in the compressor frame
for debris.
3) The second type consists of a steel
plug and O-ring assembly. The
steel plug utilized a ¼” x 20 tapped
hole to assist in removing the plug.
This plug can be removed by in-
serting a ¼” x 20 threaded rod or
bolt to pull the plug out.
5.02 INSTALLATION OF PLUG
A) Apply refrigerant grade thread sealant to the
threads of the replacement plug. Install plug
into compressor frame.
B) Rotate the compressor input shaft by hand
to make sure the compressor turns over
freely.
C) Pressurize the screw compressor package
and check for leaks.